摘要
建立了修正Johnson-Cook电塑性本构模型,使用FORTRAN语言开发了用户硬化子程序UHARD,并耦合指数形式的韧性损伤断裂准则,使用ABAQUS有限元软件进行了数值模拟。为验证本构模型与有限元模型的合理性,设计了脉冲电流辅助单向拉伸实验,通过控制脉冲电源的频率、占空比以及试验机的拉伸速度,分别在12、13和15 A·mm^(-2)电流密度下对Ti6554试样进行拉伸,直至断裂。结果表明,模拟与实验的载荷-位移、温度-时间曲线吻合情况良好,试样在15 A·mm^(-2)电流密度下的流动应力较小,温度攀升较缓,颈缩区域更广,颈缩现象提前发生,材料刚度退化最慢,最后通过扫描电子显微镜观察了3种电流密度下试样的断口形貌,发现试样均为韧性断裂。
The modified Johnson-Cook electroplastic constitutive model was established,user hardening subroutine UHARD was developed using FORTRAN language,the exponential ductile damage fracture criterion was coupled,and the numerical simulation was carried out using ABAQUS finite element software.To verify the rationality of the constitutive model and the finite element model,pulsed current assisted uniaxial tensile experiments were designed.By controlling the frequency and duty ratio of the pulse power supply and the tensile speed of the testing machine,the Ti6554 samples were tensioned until fractured at the current density of 12,13 and 15 A·mm^(-2),respectively.The results show that the load-displacement and temperature-time curves of the simulation and experiments are in good agreement.With the current density of 15 A·mm^(-2),the flow stress of the sample is small,the temperature rises slowly,the necking area is wider,the necking phenomenon occurs in advance,and the stiffness degradation of the material is the slowest.Finally,scanning electron microscope(SEM)was used to observe the fracture morphologies of the samples with three kinds of current densities,and it is found that the samples are ductile fracture.
作者
时文才
武川
周宇杰
王园园
彭志伟
SHI Wen-cai;WU Chuan;ZHOU Yu-jie;WANG Yuan-yuan;PENG Zhi-wei(National-local Joint Engineering Laboratory of Intelligent Manufacturing Oriented Automobile Die&Mould,Tianjin University of Technology and Education,Tianjin 300222,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第12期175-183,共9页
Journal of Plasticity Engineering
基金
国家自然科学基金面上资助项目(52075386)
中国博士后科学基金面上资助项目(2020M672309)
天津市自然科学基金多投入重点项目(22JCZDJC00650)
天津市教委科研项目(2020KJ107)
陕西省高性能精确成形技术与装备重点实验室开放课题(PETE2019KF02)。
关键词
Ti6554钛合金
电塑性拉伸
损伤断裂
数值模拟
二次开发
Ti6554 titanium alloy
electroplastic tension
damage fracture
numerical simulation
secondary development
